On one of the rare occasions I've used Lightroom Collections, I found myself wanting to transfer the Pick/Reject info from the Collection back to the main Folder the photos are in. Picks are Collection-local, and there doesn't seem to be a built-in way of doing it. The best I could come up with is using a tag or coloured flag (which are global) as a temporary marker, allowing me to edit the Picks in the Folder. Is there a better way?

For me, this issue is a real bugbear. I actually see it as a defect of the software and it is one of the more compelling reasons to upgrade to Lightroom 4, where flag status is global, rather than local to a Collection.